The US Department of the Treasury on Thursday expanded sanctions on Russia.

The United States has expanded sanctions against Russia over its support for anti-Kiev fighters in Ukraine and the 2014 reunification of the Crimean peninsula with the Russian mainland.

In an updated sanctions blacklist issued on Thursday, the US Department of the Treasury targeted companies building a multi-billion dollar bridge to link Russia with Crimea, and also added dozens of people and companies to the list. Those blacklisted include dozens of Russian companies and up to 37 individuals.

The Treasury pointed out seven companies which it said are directly involved in the construction of the 19 km (11.8 miles) road-and-rail connection across the Kerch Strait, which connects the Black Sea and the Sea of Azov.

The Treasury also named several subsidiaries of Russian gas giant Gazprom and 11 Crimean officials.

“Russia continues to provoke instability in eastern Ukraine despite its Minsk commitments,” said John Smith, acting director of the Treasury’s Office of Foreign Assets Control, which imposes sanctions.

“Treasury stands with our partners in condemning Russia’s violation of international law, and we will continue to sanction those who threaten Ukraine’s peace, security and sovereignty.”

A view through a construction fence shows the Kremlin towers and St. Basil’s Cathedral on a hot summer day in central Moscow, Russia, July 1, 2016. (Reuters photo)

Crimea declared independence from Ukraine on March 17, 2014, and formally applied to become part of Russia following a referendum in which 96.8 percent of participants voted in favor of the secession. The voter turnout in the referendum stood at 83.1 percent.

Since then, the US and some other Western countries have imposed several rounds of sanctions against Russia over accusations that Moscow has been involved in a deadly crisis in Ukraine, which broke out when Kiev launched military operations to crack down on pro-Russia forces in eastern Ukraine last year. Russia has denied the allegation.

Earlier this year, US President Barack Obama signed a new Executive Order that extends economic sanctions against Russia for another year.

The decree, published on March 2 on the official White House website, states that economic and financial sanctions imposed on Moscow over its involvement in the Ukrainian crisis will stay in place until March 6, 2017.

US President Barack Obama (L) and Russian President Vladimir Putin (file photo)

The decision came as “Russia’s actions continue to pose an unusual and extraordinary threat to the national security and foreign policy of the United States,” Obama said in the document.

The sanctions were originally introduced against Moscow in March 2014, after Ukraine’s Black Sea peninsula of Crimea joined Russia.

In Ukraine, the violence intensified in April 2014, after Kiev deployed troops to the eastern Ukrainian regions of Luhansk and Donetsk to suppress pro-Russians. More than 9,000 people have been killed in the conflict.